1. Field of the Invention
The present invention relates to a sewing machine adapted to apply ribbon-like trimmings to a workpiece, of the type comprising: a bed at the top of which a work table is defined, along which table the workpiece to be fed is advanced; a head held in cantilevered fashion above the work table; a presser foot oscillatably connected to the head and spring pushed towards the work table for pressing the workpiece against the work table itself; sewing means operating through the work table in the region of the presser foot in order to sew the workpiece.
2. Known Art
It is known that when workpieces are sewn together in order to make garments or other articles, provision is often made for operating steps in which a piece of ribbon-like trimmings must be applied along the edge of the workpiece being worked. These operating steps are currently carried out by specific sewing machines provided with a bordering guide fastened to the machine bed and suitably conformed so that the ribbon-like trimmings, travelling along the bordering guide, can be folded over lengthwise leaving then the bordering guide when they reach the outlet end thereof which is located before the presser foot. At said outlet end, the folded ribbon-like trimmings are then engaged on either side of the workpiece edge, so that they can be fastened thereto when the stitching is carried out.
When the stitching is completed the piece of trimmings is cut downstream of the presser foot so that an end portion thereof is clamped under the presser foot, which will allow an easy engagement of said piece of trimmings to the next workpiece.
While they can perfectly perform the functions, sewing machines of the above type have some drawbacks as regards versatility and practical use.
In fact the fixed positioning of the bordering guide having its outlet end just before the presser foot involves some difficulties in carrying out sewings when the application of ribbon-like trimmings is not involved. In addition, at the present state of the art important problems arise when it is necessary to carry out the sewing of two different pieces of trimmings on a workpiece with one and the same machine. In this connection it is to be pointed out first of all that two different pieces of trimming cannot be applied with the same machine if said pieces are very different in width. In fact the shape and size features of the bordering guide are strictly related to the width of the piece of trimming to be applied.
In addition, when the piece of trimming to be applied to the workpiece need to be replaced by a different one, it is necessary to stop the working so as to take off the previously used trimming from the bordering guide and put the new one thereinto. It will be understood that when mass production is involved, the plurality of interruptions in working in order to change the pieces of trimming brings about important idle times in production.